The continuing evolution of hydroacoustic transducer design has resulted in the extensive use of ferroelectric elements functioning to project acoustic energy representative of driving potentials and to create representative signals when acoustic energy impinges on an appropriately impedance matched surface. Three evolving designs which reflect an advanced state of the art are shown by Frank R. Abbott in the patented embodiments of U.S. Patent and Trademark Office, No. 3,100,291; 3,700,939; and 3,718,897. These devices employ stacks of piezoelectric discs or ferroelectric rings as the driving-sensing elements in projectors or receivers of acoustic energy. The stacked elements are suitably polarized and have silver coated electrodes, thin leaf conductors and the like affixed to the ferroelectric elements with the whole lot being cemented and soldered together to unify the structure. This fabrication mode has worked well. The three designs identified above have functioned within and often exceeded their design expectations. However, all involved a rather laborious assembly procedure which tended to compromise their cost effectiveness. The disc-shaped and ring-shaped active elements were somewhat more expensive to make and, from time-to-time when high driving potentials were applied, the bonded stacks might damage themselves or pull apart from the conductor leaves and films.
Therefore, there is a continuing need in the state of the art for a hydroacoustic transducer which avoids a laborious fabrication procedure and its attendant costs.